Google is testing a rounded corner design for the favicons displayed in the mobile search results on snippets. Brodie Clark shared some examples on Twitter saying "On the back of recent testing of favicon sizing on mobile, a rounded version with a grey background has appeared. Similar to previous tests, the brand name/domain is also repeated at the top."
Here is a snippet of the rounded favicon test (click to enlarge):
Compare that to the normal squared off corners (click to enlarge):
Here are more examples from Brodie:
I think we have a winner. On the back of recent testing of favicon sizing on mobile, a rounded version with a grey background has appeared. Similar to previous tests, the brand name/domain is also repeated at the top. High res image & SERP timeline: https://t.co/j6IUtkSa1z pic.twitter.com/1ETLGp1IXv
— Brodie Clark (@brodieseo) June 22, 2022
I think the rounded look gives them more uniformity in the search results interface.
Forum discussion at Twitter.